99Hawk262

iTrader: (19)

Wanting to add heads to my combo, and was looking at the PRC offerings. Question is, which ones would better compliment this cam? The stage 2.5 5.3, or the LS6 heads? Also, how much could I mill them? I will also be adding a Racetronix pump/hot wire kit and FIC 36-pound injectors, and most likely going back to a Yank PT4400 converter. Just wanting to mix things up a little and add some power. Thanks for any inputs...

Camaroking1996

Neither. You will get better results out of fully ported 243's

01ssreda4

iTrader: (96)

LS6 Castings all the way. I never have been a fan of the 5.3s. Here's a set I had done:

https://ls1tech.com/forums/generatio...-cnc-work.html

99Hawk262

iTrader: (19)

So get a set of 243's and basically send them in to AI...sounds easy enough. What can I mill them to safely?

TXZ28LS1

iTrader: (5)

Hawk,

You know i run the reverse split also. I think the best results that came with a reverse split are LS6 heads. If you go back and look at all the results, most of the results are with the reverse split. I would look into WCCH, or TEA.

01ssreda4

iTrader: (96)

Talk it over with A.I. Mine are done a total of around .040 and shooting for 11:1 compression.

senicalj4579

iTrader: (41)

Why is everyone so against the prc tsp 243/799? I thought they were full cnc also?
Even the 5.3 why is everyone so against these? AI told me the 5.3 will produce the same or very close power as the 243/799.

01ssreda4

iTrader: (96)

I'm not against the 5.3s, but they are not as good of a casting design to my understanding. They do make slightly more compression but with slightly smaller valves. Maybe A.I. can work their magic and make them perform but I think an equally done 243 will perform better. Plus I have seen/read/heard of lots of cars that run mediocre times with CNC'd 5.3s, so I just kinda steer clear. But understand I'm not saying they won't perform, it's just I haven't really been impressed overall.

thunderstruck507

iTrader: (18)

Agreed, especially since the cost difference is negligible it seems.

Often salvage yards have 799 heads cheap or you can find deals on them and send them for cores or porting.

BigBirdLS1

Check my numbers OP I just added PRC 2.5 5.3 heads. I am impressed and I believe the heads come with the same size valves as stock 243's or maybe a little bigger I can't remember.